:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #64748b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --background: #ffffff;
    --background-light: #f8fafc;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --error-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.navbar {
    background: var(--background);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    object-fit: cover;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.cart-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    position: relative;
}

.cart-count {
    position: absolute;
    top: -8px;
    right: -8px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
}

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

.features {
    padding: 5rem 0;
    background: var(--background-light);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.feature-icon svg {
    stroke: white;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.about-courses {
    padding: 5rem 0;
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.about-content h3 {
    color: var(--text-primary);
    font-size: 1.75rem;
    margin: 2rem 0 1rem;
}

.about-content p {
    margin-bottom: 1.5rem;
}

.products {
    padding: 5rem 0;
    background: var(--background-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.product-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s, box-shadow 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.product-image {
    width: 100%;
    height: 240px;
    overflow: hidden;
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.product-card:hover .product-image img {
    transform: scale(1.05);
}

.product-info {
    padding: 1.5rem;
}

.product-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.product-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.product-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.admin-preview {
    padding: 5rem 0;
}

.admin-frame {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    margin-top: 2rem;
}

.admin-header {
    background: var(--primary-color);
    color: white;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 600;
}

.admin-content {
    display: flex;
    min-height: 500px;
}

.admin-sidebar {
    width: 250px;
    background: var(--background-light);
    padding: 1.5rem 0;
    border-right: 1px solid var(--border-color);
}

.admin-menu-item {
    padding: 0.875rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--text-secondary);
}

.admin-menu-item:hover,
.admin-menu-item.active {
    background: white;
    color: var(--primary-color);
}

.admin-main {
    flex: 1;
    padding: 2rem;
}

.admin-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.admin-stat-card {
    background: var(--background-light);
    padding: 1.5rem;
    border-radius: 8px;
}

.admin-stat-title {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.admin-stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.admin-stat-change {
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

.admin-stat-change.positive {
    color: var(--success-color);
}

.admin-chart {
    background: var(--background-light);
    border-radius: 8px;
    padding: 1.5rem;
}

.admin-chart-header {
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.admin-chart-body {
    display: flex;
    align-items: flex-end;
    gap: 1rem;
    height: 200px;
}

.chart-bar {
    flex: 1;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 4px 4px 0 0;
    transition: opacity 0.3s;
}

.chart-bar:hover {
    opacity: 0.8;
}

.product-detail {
    padding: 3rem 0;
}

.product-detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.product-detail-image img {
    width: 100%;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.product-detail h1 {
    font-size: 2.25rem;
    margin-bottom: 1rem;
}

.product-detail-price {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.product-detail-description {
    margin-bottom: 2rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.product-features {
    margin-bottom: 2rem;
}

.product-features h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.product-features ul {
    list-style: none;
    padding: 0;
}

.product-features li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.product-features li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

.product-actions {
    display: flex;
    gap: 1rem;
}

.cart-container,
.checkout-container,
.contact-container,
.success-container {
    padding: 3rem 0;
    min-height: 60vh;
}

.cart-container h1,
.checkout-container h1,
.contact-container h1,
.success-container h1 {
    text-align: center;
    margin-bottom: 2rem;
}

.cart-item {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-bottom: 1rem;
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.cart-item-image {
    width: 120px;
    height: 120px;
    border-radius: 8px;
    overflow: hidden;
}

.cart-item-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.cart-item-info {
    flex: 1;
}

.cart-item-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.cart-item-price {
    font-size: 1.25rem;
    color: var(--primary-color);
    font-weight: 700;
}

.cart-item-remove {
    background: var(--error-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: opacity 0.3s;
}

.cart-item-remove:hover {
    opacity: 0.8;
}

.cart-summary {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    margin-top: 2rem;
    text-align: right;
}

.cart-total {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.cart-total span {
    color: var(--primary-color);
}

.cart-empty {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.checkout-form,
.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 2rem;
}

.contact-info {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
}

.contact-info h2 {
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.contact-item-icon {
    width: 48px;
    height: 48px;
    background: var(--background-light);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-item-icon svg {
    stroke: var(--primary-color);
}

.contact-item-content h3 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.contact-item-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.success-icon {
    width: 80px;
    height: 80px;
    background: var(--success-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
}

.success-icon svg {
    stroke: white;
}

.success-container {
    text-align: center;
}

.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s;
}

.social-links a:hover {
    background: var(--primary-color);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: white;
}

.footer-contacts {
    list-style: none;
}

.footer-contacts li {
    display: flex;
    align-items: start;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

.footer-contacts svg {
    flex-shrink: 0;
    margin-top: 2px;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.cookie-banner {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    max-width: 600px;
    width: 90%;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-xl);
    z-index: 2000;
    display: none;
}

.cookie-banner.show {
    display: block;
}

.cookie-content h3 {
    margin-bottom: 0.75rem;
}

.cookie-content p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.cookie-small {
    font-size: 0.875rem;
}

.cookie-small a {
    color: var(--primary-color);
}

.cookie-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    background: white;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow-xl);
    z-index: 3000;
    display: none;
    align-items: center;
    gap: 0.75rem;
}

.notification.show {
    display: flex;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .features-grid,
    .products-grid {
        grid-template-columns: 1fr;
    }

    .product-detail-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .admin-content {
        flex-direction: column;
    }

    .admin-sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}